14mm 3Mhz PZT5 Half Moon Piezo Ceramic Element for Baby Fetal Heart Rate Monitor

Description

This half moon piezo ceramic element is semicircle shape. It’s special for baby fetal doppler heart rate monitor. The diameter of this PZT piezoelectric crystal disc diameter is 14mm. Its thickness is 7mm and frequency is 3MHz. It is semicircular and size is custom. We can also provide other frequencies, such as 1MHz, 2MHz, 2.2MHz, 2.5MHz, 2.6MHz, 3MHz, 3.5MHz, 4MHz, 5MHz, 10MHz, etc. And other available diameters are 10mm, 15mm, 16mm, 20mm, 22mm, 25mm, 28mm, 30mm, etc.

Technical specifications of semicircle piezoelectric crystal half disc:

PZT material: PZT5;
Pizo disc size: half moom 14*7mm;
Resonant frequency: 2950~3100 khz;
Resonant impedance: ≤3Ω;
Electromechanical coupling coefficient:≥0.5;
Static capacitance: 1200~1800 pF;
Electrode type: the positive and negative electrodes are distributed on the same side;
Application: doppler, baby foetal heartbeat monitor element, fetal heart rate monitor element, ultrasound fetal heart monitoring, ultrasound scan;

How does the half moon piezo ceramic element work in a fetal heart rate monitor?

Place the fetal heart monitor probe firmly against the abdominal wall, directly facing the fetal heart. Then connect headphones. You can hear the fetal heartbeat. Therefore, pregnant women can monitor their babies at home at any time. When they feel unwell, they can count the fetal heart rate and fetal movements. If any problems, they can go to the hospital for treatment promptly.

This fetal heart rate monitor probe is a piezoelectric ultrasonic Doppler probe. The probe uses two semi-circular piezoelectric ceramic element. This PZT crystal half discs have piezoelectric effect. One is used to transmit signals. And the other is for receiving signals.

(1) Emit ultrasonic waves

The half moon piezo ceramic is excited by the monitor circuit. Then it will generate the inverse piezoelectric effect. Under the influence of an electric field, the ceramic vibrates mechanically. The Doppler probe emits ultrasound waves towards the pregnant woman’s abdomen. Ultrasound waves pass through human tissue, and some are reflected. This includes reflected waves that hit the fetal heart.

(2) Receive ultrasound waves

The reflected waves act on the ceramic element. This induces a positive piezoelectric effect. The ceramic converts the received ultrasonic mechanical vibrations into electrical signals.These weak electrical signals are collected by the probe. Then probe transmits these signals to the fetal heart rate monitor.

(3) Signal Processing and Display

The monitor performs a series of processing steps on electrical signals, such as amplification, filtering, and analysis. Then it can calculate the frequency of the fetal heartbeat. Then it is displayed to medical staff in the form of numbers, waveforms, or sound. This allows for the monitoring of the fetal heart rate.

So that’s the working principle of half moon piezo ceramic in baby fetal heart rate monitor.